1 //===-- RISCVAsmParser.cpp - Parse RISCV assembly to MCInst instructions --===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "MCTargetDesc/RISCVAsmBackend.h"
10 #include "MCTargetDesc/RISCVMCExpr.h"
11 #include "MCTargetDesc/RISCVMCTargetDesc.h"
12 #include "MCTargetDesc/RISCVTargetStreamer.h"
13 #include "TargetInfo/RISCVTargetInfo.h"
14 #include "Utils/RISCVBaseInfo.h"
15 #include "Utils/RISCVMatInt.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallBitVector.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/ADT/StringSwitch.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCExpr.h"
25 #include "llvm/MC/MCInst.h"
26 #include "llvm/MC/MCInstBuilder.h"
27 #include "llvm/MC/MCObjectFileInfo.h"
28 #include "llvm/MC/MCParser/MCAsmLexer.h"
29 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
30 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
31 #include "llvm/MC/MCRegisterInfo.h"
32 #include "llvm/MC/MCStreamer.h"
33 #include "llvm/MC/MCSubtargetInfo.h"
34 #include "llvm/MC/MCValue.h"
35 #include "llvm/Support/Casting.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Support/RISCVAttributes.h"
38 #include "llvm/Support/TargetRegistry.h"
39 
40 #include <limits>
41 
42 using namespace llvm;
43 
44 #define DEBUG_TYPE "riscv-asm-parser"
45 
46 // Include the auto-generated portion of the compress emitter.
47 #define GEN_COMPRESS_INSTR
48 #include "RISCVGenCompressInstEmitter.inc"
49 
50 STATISTIC(RISCVNumInstrsCompressed,
51           "Number of RISC-V Compressed instructions emitted");
52 
53 namespace {
54 struct RISCVOperand;
55 
56 struct ParserOptionsSet {
57   bool IsPicEnabled;
58 };
59 
60 class RISCVAsmParser : public MCTargetAsmParser {
61   SmallVector<FeatureBitset, 4> FeatureBitStack;
62 
63   SmallVector<ParserOptionsSet, 4> ParserOptionsStack;
64   ParserOptionsSet ParserOptions;
65 
66   SMLoc getLoc() const { return getParser().getTok().getLoc(); }
67   bool isRV64() const { return getSTI().hasFeature(RISCV::Feature64Bit); }
68   bool isRV32E() const { return getSTI().hasFeature(RISCV::FeatureRV32E); }
69 
70   RISCVTargetStreamer &getTargetStreamer() {
71     MCTargetStreamer &TS = *getParser().getStreamer().getTargetStreamer();
72     return static_cast<RISCVTargetStreamer &>(TS);
73   }
74 
75   unsigned validateTargetOperandClass(MCParsedAsmOperand &Op,
76                                       unsigned Kind) override;
77 
78   bool generateImmOutOfRangeError(OperandVector &Operands, uint64_t ErrorInfo,
79                                   int64_t Lower, int64_t Upper, Twine Msg);
80 
81   bool MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
82                                OperandVector &Operands, MCStreamer &Out,
83                                uint64_t &ErrorInfo,
84                                bool MatchingInlineAsm) override;
85 
86   bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc, SMLoc &EndLoc) override;
87   OperandMatchResultTy tryParseRegister(unsigned &RegNo, SMLoc &StartLoc,
88                                         SMLoc &EndLoc) override;
89 
90   bool ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
91                         SMLoc NameLoc, OperandVector &Operands) override;
92 
93   bool ParseDirective(AsmToken DirectiveID) override;
94 
95   // Helper to actually emit an instruction to the MCStreamer. Also, when
96   // possible, compression of the instruction is performed.
97   void emitToStreamer(MCStreamer &S, const MCInst &Inst);
98 
99   // Helper to emit a combination of LUI, ADDI(W), and SLLI instructions that
100   // synthesize the desired immedate value into the destination register.
101   void emitLoadImm(MCRegister DestReg, int64_t Value, MCStreamer &Out);
102 
103   // Helper to emit a combination of AUIPC and SecondOpcode. Used to implement
104   // helpers such as emitLoadLocalAddress and emitLoadAddress.
105   void emitAuipcInstPair(MCOperand DestReg, MCOperand TmpReg,
106                          const MCExpr *Symbol, RISCVMCExpr::VariantKind VKHi,
107                          unsigned SecondOpcode, SMLoc IDLoc, MCStreamer &Out);
108 
109   // Helper to emit pseudo instruction "lla" used in PC-rel addressing.
110   void emitLoadLocalAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
111 
112   // Helper to emit pseudo instruction "la" used in GOT/PC-rel addressing.
113   void emitLoadAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
114 
115   // Helper to emit pseudo instruction "la.tls.ie" used in initial-exec TLS
116   // addressing.
117   void emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
118 
119   // Helper to emit pseudo instruction "la.tls.gd" used in global-dynamic TLS
120   // addressing.
121   void emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
122 
123   // Helper to emit pseudo load/store instruction with a symbol.
124   void emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode, SMLoc IDLoc,
125                            MCStreamer &Out, bool HasTmpReg);
126 
127   // Checks that a PseudoAddTPRel is using x4/tp in its second input operand.
128   // Enforcing this using a restricted register class for the second input
129   // operand of PseudoAddTPRel results in a poor diagnostic due to the fact
130   // 'add' is an overloaded mnemonic.
131   bool checkPseudoAddTPRel(MCInst &Inst, OperandVector &Operands);
132 
133   // Check instruction constraints.
134   bool validateInstruction(MCInst &Inst, OperandVector &Operands);
135 
136   /// Helper for processing MC instructions that have been successfully matched
137   /// by MatchAndEmitInstruction. Modifications to the emitted instructions,
138   /// like the expansion of pseudo instructions (e.g., "li"), can be performed
139   /// in this method.
140   bool processInstruction(MCInst &Inst, SMLoc IDLoc, OperandVector &Operands,
141                           MCStreamer &Out);
142 
143 // Auto-generated instruction matching functions
144 #define GET_ASSEMBLER_HEADER
145 #include "RISCVGenAsmMatcher.inc"
146 
147   OperandMatchResultTy parseCSRSystemRegister(OperandVector &Operands);
148   OperandMatchResultTy parseImmediate(OperandVector &Operands);
149   OperandMatchResultTy parseRegister(OperandVector &Operands,
150                                      bool AllowParens = false);
151   OperandMatchResultTy parseMemOpBaseReg(OperandVector &Operands);
152   OperandMatchResultTy parseAtomicMemOp(OperandVector &Operands);
153   OperandMatchResultTy parseOperandWithModifier(OperandVector &Operands);
154   OperandMatchResultTy parseBareSymbol(OperandVector &Operands);
155   OperandMatchResultTy parseCallSymbol(OperandVector &Operands);
156   OperandMatchResultTy parsePseudoJumpSymbol(OperandVector &Operands);
157   OperandMatchResultTy parseJALOffset(OperandVector &Operands);
158   OperandMatchResultTy parseVTypeI(OperandVector &Operands);
159   OperandMatchResultTy parseMaskReg(OperandVector &Operands);
160 
161   bool parseOperand(OperandVector &Operands, StringRef Mnemonic);
162 
163   bool parseDirectiveOption();
164   bool parseDirectiveAttribute();
165 
166   void setFeatureBits(uint64_t Feature, StringRef FeatureString) {
167     if (!(getSTI().getFeatureBits()[Feature])) {
168       MCSubtargetInfo &STI = copySTI();
169       setAvailableFeatures(
170           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
171     }
172   }
173 
174   bool getFeatureBits(uint64_t Feature) {
175     return getSTI().getFeatureBits()[Feature];
176   }
177 
178   void clearFeatureBits(uint64_t Feature, StringRef FeatureString) {
179     if (getSTI().getFeatureBits()[Feature]) {
180       MCSubtargetInfo &STI = copySTI();
181       setAvailableFeatures(
182           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
183     }
184   }
185 
186   void pushFeatureBits() {
187     assert(FeatureBitStack.size() == ParserOptionsStack.size() &&
188            "These two stacks must be kept synchronized");
189     FeatureBitStack.push_back(getSTI().getFeatureBits());
190     ParserOptionsStack.push_back(ParserOptions);
191   }
192 
193   bool popFeatureBits() {
194     assert(FeatureBitStack.size() == ParserOptionsStack.size() &&
195            "These two stacks must be kept synchronized");
196     if (FeatureBitStack.empty())
197       return true;
198 
199     FeatureBitset FeatureBits = FeatureBitStack.pop_back_val();
200     copySTI().setFeatureBits(FeatureBits);
201     setAvailableFeatures(ComputeAvailableFeatures(FeatureBits));
202 
203     ParserOptions = ParserOptionsStack.pop_back_val();
204 
205     return false;
206   }
207 
208   std::unique_ptr<RISCVOperand> defaultMaskRegOp() const;
209 
210 public:
211   enum RISCVMatchResultTy {
212     Match_Dummy = FIRST_TARGET_MATCH_RESULT_TY,
213 #define GET_OPERAND_DIAGNOSTIC_TYPES
214 #include "RISCVGenAsmMatcher.inc"
215 #undef GET_OPERAND_DIAGNOSTIC_TYPES
216   };
217 
218   static bool classifySymbolRef(const MCExpr *Expr,
219                                 RISCVMCExpr::VariantKind &Kind);
220 
221   RISCVAsmParser(const MCSubtargetInfo &STI, MCAsmParser &Parser,
222                  const MCInstrInfo &MII, const MCTargetOptions &Options)
223       : MCTargetAsmParser(Options, STI, MII) {
224     Parser.addAliasForDirective(".half", ".2byte");
225     Parser.addAliasForDirective(".hword", ".2byte");
226     Parser.addAliasForDirective(".word", ".4byte");
227     Parser.addAliasForDirective(".dword", ".8byte");
228     setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
229 
230     auto ABIName = StringRef(Options.ABIName);
231     if (ABIName.endswith("f") &&
232         !getSTI().getFeatureBits()[RISCV::FeatureStdExtF]) {
233       errs() << "Hard-float 'f' ABI can't be used for a target that "
234                 "doesn't support the F instruction set extension (ignoring "
235                 "target-abi)\n";
236     } else if (ABIName.endswith("d") &&
237                !getSTI().getFeatureBits()[RISCV::FeatureStdExtD]) {
238       errs() << "Hard-float 'd' ABI can't be used for a target that "
239                 "doesn't support the D instruction set extension (ignoring "
240                 "target-abi)\n";
241     }
242 
243     const MCObjectFileInfo *MOFI = Parser.getContext().getObjectFileInfo();
244     ParserOptions.IsPicEnabled = MOFI->isPositionIndependent();
245   }
246 };
247 
248 /// RISCVOperand - Instances of this class represent a parsed machine
249 /// instruction
250 struct RISCVOperand : public MCParsedAsmOperand {
251 
252   enum class KindTy {
253     Token,
254     Register,
255     Immediate,
256     SystemRegister,
257     VType,
258   } Kind;
259 
260   bool IsRV64;
261 
262   struct RegOp {
263     MCRegister RegNum;
264   };
265 
266   struct ImmOp {
267     const MCExpr *Val;
268   };
269 
270   struct SysRegOp {
271     const char *Data;
272     unsigned Length;
273     unsigned Encoding;
274     // FIXME: Add the Encoding parsed fields as needed for checks,
275     // e.g.: read/write or user/supervisor/machine privileges.
276   };
277 
278   enum class VSEW {
279     SEW_8 = 0,
280     SEW_16,
281     SEW_32,
282     SEW_64,
283     SEW_128,
284     SEW_256,
285     SEW_512,
286     SEW_1024,
287   };
288 
289   enum class VLMUL {
290     LMUL_1 = 0,
291     LMUL_2,
292     LMUL_4,
293     LMUL_8,
294     LMUL_F8 = 5,
295     LMUL_F4,
296     LMUL_F2
297   };
298 
299   struct VTypeOp {
300     VSEW Sew;
301     VLMUL Lmul;
302     bool TailAgnostic;
303     bool MaskedoffAgnostic;
304     unsigned Encoding;
305   };
306 
307   SMLoc StartLoc, EndLoc;
308   union {
309     StringRef Tok;
310     RegOp Reg;
311     ImmOp Imm;
312     struct SysRegOp SysReg;
313     struct VTypeOp VType;
314   };
315 
316   RISCVOperand(KindTy K) : MCParsedAsmOperand(), Kind(K) {}
317 
318 public:
319   RISCVOperand(const RISCVOperand &o) : MCParsedAsmOperand() {
320     Kind = o.Kind;
321     IsRV64 = o.IsRV64;
322     StartLoc = o.StartLoc;
323     EndLoc = o.EndLoc;
324     switch (Kind) {
325     case KindTy::Register:
326       Reg = o.Reg;
327       break;
328     case KindTy::Immediate:
329       Imm = o.Imm;
330       break;
331     case KindTy::Token:
332       Tok = o.Tok;
333       break;
334     case KindTy::SystemRegister:
335       SysReg = o.SysReg;
336       break;
337     case KindTy::VType:
338       VType = o.VType;
339       break;
340     }
341   }
342 
343   bool isToken() const override { return Kind == KindTy::Token; }
344   bool isReg() const override { return Kind == KindTy::Register; }
345   bool isV0Reg() const {
346     return Kind == KindTy::Register && Reg.RegNum == RISCV::V0;
347   }
348   bool isImm() const override { return Kind == KindTy::Immediate; }
349   bool isMem() const override { return false; }
350   bool isSystemRegister() const { return Kind == KindTy::SystemRegister; }
351   bool isVType() const { return Kind == KindTy::VType; }
352 
353   bool isGPR() const {
354     return Kind == KindTy::Register &&
355            RISCVMCRegisterClasses[RISCV::GPRRegClassID].contains(Reg.RegNum);
356   }
357 
358   static bool evaluateConstantImm(const MCExpr *Expr, int64_t &Imm,
359                                   RISCVMCExpr::VariantKind &VK) {
360     if (auto *RE = dyn_cast<RISCVMCExpr>(Expr)) {
361       VK = RE->getKind();
362       return RE->evaluateAsConstant(Imm);
363     }
364 
365     if (auto CE = dyn_cast<MCConstantExpr>(Expr)) {
366       VK = RISCVMCExpr::VK_RISCV_None;
367       Imm = CE->getValue();
368       return true;
369     }
370 
371     return false;
372   }
373 
374   // True if operand is a symbol with no modifiers, or a constant with no
375   // modifiers and isShiftedInt<N-1, 1>(Op).
376   template <int N> bool isBareSimmNLsb0() const {
377     int64_t Imm;
378     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
379     if (!isImm())
380       return false;
381     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
382     bool IsValid;
383     if (!IsConstantImm)
384       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
385     else
386       IsValid = isShiftedInt<N - 1, 1>(Imm);
387     return IsValid && VK == RISCVMCExpr::VK_RISCV_None;
388   }
389 
390   // Predicate methods for AsmOperands defined in RISCVInstrInfo.td
391 
392   bool isBareSymbol() const {
393     int64_t Imm;
394     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
395     // Must be of 'immediate' type but not a constant.
396     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
397       return false;
398     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
399            VK == RISCVMCExpr::VK_RISCV_None;
400   }
401 
402   bool isCallSymbol() const {
403     int64_t Imm;
404     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
405     // Must be of 'immediate' type but not a constant.
406     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
407       return false;
408     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
409            (VK == RISCVMCExpr::VK_RISCV_CALL ||
410             VK == RISCVMCExpr::VK_RISCV_CALL_PLT);
411   }
412 
413   bool isPseudoJumpSymbol() const {
414     int64_t Imm;
415     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
416     // Must be of 'immediate' type but not a constant.
417     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
418       return false;
419     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
420            VK == RISCVMCExpr::VK_RISCV_CALL;
421   }
422 
423   bool isTPRelAddSymbol() const {
424     int64_t Imm;
425     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
426     // Must be of 'immediate' type but not a constant.
427     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
428       return false;
429     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
430            VK == RISCVMCExpr::VK_RISCV_TPREL_ADD;
431   }
432 
433   bool isCSRSystemRegister() const { return isSystemRegister(); }
434 
435   bool isVTypeI() const { return isVType(); }
436 
437   /// Return true if the operand is a valid for the fence instruction e.g.
438   /// ('iorw').
439   bool isFenceArg() const {
440     if (!isImm())
441       return false;
442     const MCExpr *Val = getImm();
443     auto *SVal = dyn_cast<MCSymbolRefExpr>(Val);
444     if (!SVal || SVal->getKind() != MCSymbolRefExpr::VK_None)
445       return false;
446 
447     StringRef Str = SVal->getSymbol().getName();
448     // Letters must be unique, taken from 'iorw', and in ascending order. This
449     // holds as long as each individual character is one of 'iorw' and is
450     // greater than the previous character.
451     char Prev = '\0';
452     for (char c : Str) {
453       if (c != 'i' && c != 'o' && c != 'r' && c != 'w')
454         return false;
455       if (c <= Prev)
456         return false;
457       Prev = c;
458     }
459     return true;
460   }
461 
462   /// Return true if the operand is a valid floating point rounding mode.
463   bool isFRMArg() const {
464     if (!isImm())
465       return false;
466     const MCExpr *Val = getImm();
467     auto *SVal = dyn_cast<MCSymbolRefExpr>(Val);
468     if (!SVal || SVal->getKind() != MCSymbolRefExpr::VK_None)
469       return false;
470 
471     StringRef Str = SVal->getSymbol().getName();
472 
473     return RISCVFPRndMode::stringToRoundingMode(Str) != RISCVFPRndMode::Invalid;
474   }
475 
476   bool isImmXLenLI() const {
477     int64_t Imm;
478     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
479     if (!isImm())
480       return false;
481     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
482     if (VK == RISCVMCExpr::VK_RISCV_LO || VK == RISCVMCExpr::VK_RISCV_PCREL_LO)
483       return true;
484     // Given only Imm, ensuring that the actually specified constant is either
485     // a signed or unsigned 64-bit number is unfortunately impossible.
486     return IsConstantImm && VK == RISCVMCExpr::VK_RISCV_None &&
487            (isRV64() || (isInt<32>(Imm) || isUInt<32>(Imm)));
488   }
489 
490   bool isUImmLog2XLen() const {
491     int64_t Imm;
492     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
493     if (!isImm())
494       return false;
495     if (!evaluateConstantImm(getImm(), Imm, VK) ||
496         VK != RISCVMCExpr::VK_RISCV_None)
497       return false;
498     return (isRV64() && isUInt<6>(Imm)) || isUInt<5>(Imm);
499   }
500 
501   bool isUImmLog2XLenNonZero() const {
502     int64_t Imm;
503     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
504     if (!isImm())
505       return false;
506     if (!evaluateConstantImm(getImm(), Imm, VK) ||
507         VK != RISCVMCExpr::VK_RISCV_None)
508       return false;
509     if (Imm == 0)
510       return false;
511     return (isRV64() && isUInt<6>(Imm)) || isUInt<5>(Imm);
512   }
513 
514   bool isUImmLog2XLenHalf() const {
515     int64_t Imm;
516     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
517     if (!isImm())
518       return false;
519     if (!evaluateConstantImm(getImm(), Imm, VK) ||
520         VK != RISCVMCExpr::VK_RISCV_None)
521       return false;
522     return (isRV64() && isUInt<5>(Imm)) || isUInt<4>(Imm);
523   }
524 
525   bool isUImm5() const {
526     int64_t Imm;
527     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
528     if (!isImm())
529       return false;
530     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
531     return IsConstantImm && isUInt<5>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
532   }
533 
534   bool isUImm5NonZero() const {
535     int64_t Imm;
536     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
537     if (!isImm())
538       return false;
539     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
540     return IsConstantImm && isUInt<5>(Imm) && (Imm != 0) &&
541            VK == RISCVMCExpr::VK_RISCV_None;
542   }
543 
544   bool isSImm5() const {
545     if (!isImm())
546       return false;
547     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
548     int64_t Imm;
549     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
550     return IsConstantImm && isInt<5>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
551   }
552 
553   bool isSImm6() const {
554     if (!isImm())
555       return false;
556     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
557     int64_t Imm;
558     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
559     return IsConstantImm && isInt<6>(Imm) &&
560 	    VK == RISCVMCExpr::VK_RISCV_None;
561   }
562 
563   bool isSImm6NonZero() const {
564     if (!isImm())
565       return false;
566     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
567     int64_t Imm;
568     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
569     return IsConstantImm && isInt<6>(Imm) && (Imm != 0) &&
570            VK == RISCVMCExpr::VK_RISCV_None;
571   }
572 
573   bool isCLUIImm() const {
574     if (!isImm())
575       return false;
576     int64_t Imm;
577     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
578     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
579     return IsConstantImm && (Imm != 0) &&
580            (isUInt<5>(Imm) || (Imm >= 0xfffe0 && Imm <= 0xfffff)) &&
581            VK == RISCVMCExpr::VK_RISCV_None;
582   }
583 
584   bool isUImm7Lsb00() const {
585     if (!isImm())
586       return false;
587     int64_t Imm;
588     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
589     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
590     return IsConstantImm && isShiftedUInt<5, 2>(Imm) &&
591            VK == RISCVMCExpr::VK_RISCV_None;
592   }
593 
594   bool isUImm8Lsb00() const {
595     if (!isImm())
596       return false;
597     int64_t Imm;
598     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
599     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
600     return IsConstantImm && isShiftedUInt<6, 2>(Imm) &&
601            VK == RISCVMCExpr::VK_RISCV_None;
602   }
603 
604   bool isUImm8Lsb000() const {
605     if (!isImm())
606       return false;
607     int64_t Imm;
608     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
609     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
610     return IsConstantImm && isShiftedUInt<5, 3>(Imm) &&
611            VK == RISCVMCExpr::VK_RISCV_None;
612   }
613 
614   bool isSImm9Lsb0() const { return isBareSimmNLsb0<9>(); }
615 
616   bool isUImm9Lsb000() const {
617     if (!isImm())
618       return false;
619     int64_t Imm;
620     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
621     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
622     return IsConstantImm && isShiftedUInt<6, 3>(Imm) &&
623            VK == RISCVMCExpr::VK_RISCV_None;
624   }
625 
626   bool isUImm10Lsb00NonZero() const {
627     if (!isImm())
628       return false;
629     int64_t Imm;
630     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
631     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
632     return IsConstantImm && isShiftedUInt<8, 2>(Imm) && (Imm != 0) &&
633            VK == RISCVMCExpr::VK_RISCV_None;
634   }
635 
636   bool isSImm12() const {
637     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
638     int64_t Imm;
639     bool IsValid;
640     if (!isImm())
641       return false;
642     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
643     if (!IsConstantImm)
644       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
645     else
646       IsValid = isInt<12>(Imm);
647     return IsValid && ((IsConstantImm && VK == RISCVMCExpr::VK_RISCV_None) ||
648                        VK == RISCVMCExpr::VK_RISCV_LO ||
649                        VK == RISCVMCExpr::VK_RISCV_PCREL_LO ||
650                        VK == RISCVMCExpr::VK_RISCV_TPREL_LO);
651   }
652 
653   bool isSImm12Lsb0() const { return isBareSimmNLsb0<12>(); }
654 
655   bool isSImm13Lsb0() const { return isBareSimmNLsb0<13>(); }
656 
657   bool isSImm10Lsb0000NonZero() const {
658     if (!isImm())
659       return false;
660     int64_t Imm;
661     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
662     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
663     return IsConstantImm && (Imm != 0) && isShiftedInt<6, 4>(Imm) &&
664            VK == RISCVMCExpr::VK_RISCV_None;
665   }
666 
667   bool isUImm20LUI() const {
668     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
669     int64_t Imm;
670     bool IsValid;
671     if (!isImm())
672       return false;
673     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
674     if (!IsConstantImm) {
675       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
676       return IsValid && (VK == RISCVMCExpr::VK_RISCV_HI ||
677                          VK == RISCVMCExpr::VK_RISCV_TPREL_HI);
678     } else {
679       return isUInt<20>(Imm) && (VK == RISCVMCExpr::VK_RISCV_None ||
680                                  VK == RISCVMCExpr::VK_RISCV_HI ||
681                                  VK == RISCVMCExpr::VK_RISCV_TPREL_HI);
682     }
683   }
684 
685   bool isUImm20AUIPC() const {
686     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
687     int64_t Imm;
688     bool IsValid;
689     if (!isImm())
690       return false;
691     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
692     if (!IsConstantImm) {
693       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
694       return IsValid && (VK == RISCVMCExpr::VK_RISCV_PCREL_HI ||
695                          VK == RISCVMCExpr::VK_RISCV_GOT_HI ||
696                          VK == RISCVMCExpr::VK_RISCV_TLS_GOT_HI ||
697                          VK == RISCVMCExpr::VK_RISCV_TLS_GD_HI);
698     } else {
699       return isUInt<20>(Imm) && (VK == RISCVMCExpr::VK_RISCV_None ||
700                                  VK == RISCVMCExpr::VK_RISCV_PCREL_HI ||
701                                  VK == RISCVMCExpr::VK_RISCV_GOT_HI ||
702                                  VK == RISCVMCExpr::VK_RISCV_TLS_GOT_HI ||
703                                  VK == RISCVMCExpr::VK_RISCV_TLS_GD_HI);
704     }
705   }
706 
707   bool isSImm21Lsb0JAL() const { return isBareSimmNLsb0<21>(); }
708 
709   bool isImmZero() const {
710     if (!isImm())
711       return false;
712     int64_t Imm;
713     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
714     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
715     return IsConstantImm && (Imm == 0) && VK == RISCVMCExpr::VK_RISCV_None;
716   }
717 
718   bool isSImm5Plus1() const {
719     if (!isImm())
720       return false;
721     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
722     int64_t Imm;
723     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
724     return IsConstantImm && isInt<5>(Imm - 1) &&
725            VK == RISCVMCExpr::VK_RISCV_None;
726   }
727 
728   /// getStartLoc - Gets location of the first token of this operand
729   SMLoc getStartLoc() const override { return StartLoc; }
730   /// getEndLoc - Gets location of the last token of this operand
731   SMLoc getEndLoc() const override { return EndLoc; }
732   /// True if this operand is for an RV64 instruction
733   bool isRV64() const { return IsRV64; }
734 
735   unsigned getReg() const override {
736     assert(Kind == KindTy::Register && "Invalid type access!");
737     return Reg.RegNum.id();
738   }
739 
740   StringRef getSysReg() const {
741     assert(Kind == KindTy::SystemRegister && "Invalid access!");
742     return StringRef(SysReg.Data, SysReg.Length);
743   }
744 
745   const MCExpr *getImm() const {
746     assert(Kind == KindTy::Immediate && "Invalid type access!");
747     return Imm.Val;
748   }
749 
750   StringRef getToken() const {
751     assert(Kind == KindTy::Token && "Invalid type access!");
752     return Tok;
753   }
754 
755   static StringRef getSEWStr(VSEW Sew) {
756     switch (Sew) {
757     case VSEW::SEW_8:
758       return "e8";
759     case VSEW::SEW_16:
760       return "e16";
761     case VSEW::SEW_32:
762       return "e32";
763     case VSEW::SEW_64:
764       return "e64";
765     case VSEW::SEW_128:
766       return "e128";
767     case VSEW::SEW_256:
768       return "e256";
769     case VSEW::SEW_512:
770       return "e512";
771     case VSEW::SEW_1024:
772       return "e1024";
773     }
774     llvm_unreachable("Unknown SEW.");
775   }
776 
777   static StringRef getLMULStr(VLMUL Lmul) {
778     switch (Lmul) {
779     case VLMUL::LMUL_1:
780       return "m1";
781     case VLMUL::LMUL_2:
782       return "m2";
783     case VLMUL::LMUL_4:
784       return "m4";
785     case VLMUL::LMUL_8:
786       return "m8";
787     case VLMUL::LMUL_F2:
788       return "mf2";
789     case VLMUL::LMUL_F4:
790       return "mf4";
791     case VLMUL::LMUL_F8:
792       return "mf8";
793     }
794     llvm_unreachable("Unknown LMUL.");
795   }
796 
797   StringRef getVType(SmallString<32> &Buf) const {
798     assert(Kind == KindTy::VType && "Invalid access!");
799     Buf.append(getSEWStr(VType.Sew));
800     Buf.append(",");
801     Buf.append(getLMULStr(VType.Lmul));
802 
803     return Buf.str();
804   }
805 
806   void print(raw_ostream &OS) const override {
807     switch (Kind) {
808     case KindTy::Immediate:
809       OS << *getImm();
810       break;
811     case KindTy::Register:
812       OS << "<register x";
813       OS << getReg() << ">";
814       break;
815     case KindTy::Token:
816       OS << "'" << getToken() << "'";
817       break;
818     case KindTy::SystemRegister:
819       OS << "<sysreg: " << getSysReg() << '>';
820       break;
821     case KindTy::VType:
822       SmallString<32> VTypeBuf;
823       OS << "<vtype: " << getVType(VTypeBuf) << '>';
824       break;
825     }
826   }
827 
828   static std::unique_ptr<RISCVOperand> createToken(StringRef Str, SMLoc S,
829                                                    bool IsRV64) {
830     auto Op = std::make_unique<RISCVOperand>(KindTy::Token);
831     Op->Tok = Str;
832     Op->StartLoc = S;
833     Op->EndLoc = S;
834     Op->IsRV64 = IsRV64;
835     return Op;
836   }
837 
838   static std::unique_ptr<RISCVOperand> createReg(unsigned RegNo, SMLoc S,
839                                                  SMLoc E, bool IsRV64) {
840     auto Op = std::make_unique<RISCVOperand>(KindTy::Register);
841     Op->Reg.RegNum = RegNo;
842     Op->StartLoc = S;
843     Op->EndLoc = E;
844     Op->IsRV64 = IsRV64;
845     return Op;
846   }
847 
848   static std::unique_ptr<RISCVOperand> createImm(const MCExpr *Val, SMLoc S,
849                                                  SMLoc E, bool IsRV64) {
850     auto Op = std::make_unique<RISCVOperand>(KindTy::Immediate);
851     Op->Imm.Val = Val;
852     Op->StartLoc = S;
853     Op->EndLoc = E;
854     Op->IsRV64 = IsRV64;
855     return Op;
856   }
857 
858   static std::unique_ptr<RISCVOperand>
859   createSysReg(StringRef Str, SMLoc S, unsigned Encoding, bool IsRV64) {
860     auto Op = std::make_unique<RISCVOperand>(KindTy::SystemRegister);
861     Op->SysReg.Data = Str.data();
862     Op->SysReg.Length = Str.size();
863     Op->SysReg.Encoding = Encoding;
864     Op->StartLoc = S;
865     Op->IsRV64 = IsRV64;
866     return Op;
867   }
868 
869   static std::unique_ptr<RISCVOperand>
870   createVType(APInt Sew, APInt Lmul, bool Fractional, bool TailAgnostic,
871               bool MaskedoffAgnostic, SMLoc S, bool IsRV64) {
872     auto Op = std::make_unique<RISCVOperand>(KindTy::VType);
873     Sew.ashrInPlace(3);
874     unsigned SewLog2 = Sew.logBase2();
875     unsigned LmulLog2 = Lmul.logBase2();
876     Op->VType.Sew = static_cast<VSEW>(SewLog2);
877     if (Fractional) {
878       unsigned Flmul = 8 - LmulLog2;
879       Op->VType.Lmul = static_cast<VLMUL>(Flmul);
880       Op->VType.Encoding =
881           ((Flmul & 0x4) << 3) | ((SewLog2 & 0x7) << 2) | (Flmul & 0x3);
882     } else {
883       Op->VType.Lmul = static_cast<VLMUL>(LmulLog2);
884       Op->VType.Encoding = (SewLog2 << 2) | LmulLog2;
885     }
886     if (TailAgnostic) {
887       Op->VType.Encoding |= 0x40;
888     }
889     if (MaskedoffAgnostic) {
890       Op->VType.Encoding |= 0x80;
891     }
892     Op->VType.TailAgnostic = TailAgnostic;
893     Op->VType.MaskedoffAgnostic = MaskedoffAgnostic;
894     Op->StartLoc = S;
895     Op->IsRV64 = IsRV64;
896     return Op;
897   }
898 
899   void addExpr(MCInst &Inst, const MCExpr *Expr) const {
900     assert(Expr && "Expr shouldn't be null!");
901     int64_t Imm = 0;
902     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
903     bool IsConstant = evaluateConstantImm(Expr, Imm, VK);
904 
905     if (IsConstant)
906       Inst.addOperand(MCOperand::createImm(Imm));
907     else
908       Inst.addOperand(MCOperand::createExpr(Expr));
909   }
910 
911   // Used by the TableGen Code
912   void addRegOperands(MCInst &Inst, unsigned N) const {
913     assert(N == 1 && "Invalid number of operands!");
914     Inst.addOperand(MCOperand::createReg(getReg()));
915   }
916 
917   void addImmOperands(MCInst &Inst, unsigned N) const {
918     assert(N == 1 && "Invalid number of operands!");
919     addExpr(Inst, getImm());
920   }
921 
922   void addSImm5Plus1Operands(MCInst &Inst, unsigned N) const {
923     assert(N == 1 && "Invalid number of operands!");
924     int64_t Imm = 0;
925     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
926     bool IsConstant = evaluateConstantImm(getImm(), Imm, VK);
927     assert(IsConstant && "Expect constant value!");
928     (void)IsConstant;
929     Inst.addOperand(MCOperand::createImm(Imm - 1));
930   }
931 
932   void addFenceArgOperands(MCInst &Inst, unsigned N) const {
933     assert(N == 1 && "Invalid number of operands!");
934     // isFenceArg has validated the operand, meaning this cast is safe
935     auto SE = cast<MCSymbolRefExpr>(getImm());
936 
937     unsigned Imm = 0;
938     for (char c : SE->getSymbol().getName()) {
939       switch (c) {
940       default:
941         llvm_unreachable("FenceArg must contain only [iorw]");
942       case 'i': Imm |= RISCVFenceField::I; break;
943       case 'o': Imm |= RISCVFenceField::O; break;
944       case 'r': Imm |= RISCVFenceField::R; break;
945       case 'w': Imm |= RISCVFenceField::W; break;
946       }
947     }
948     Inst.addOperand(MCOperand::createImm(Imm));
949   }
950 
951   void addCSRSystemRegisterOperands(MCInst &Inst, unsigned N) const {
952     assert(N == 1 && "Invalid number of operands!");
953     Inst.addOperand(MCOperand::createImm(SysReg.Encoding));
954   }
955 
956   void addVTypeIOperands(MCInst &Inst, unsigned N) const {
957     assert(N == 1 && "Invalid number of operands!");
958     Inst.addOperand(MCOperand::createImm(VType.Encoding));
959   }
960 
961   // Returns the rounding mode represented by this RISCVOperand. Should only
962   // be called after checking isFRMArg.
963   RISCVFPRndMode::RoundingMode getRoundingMode() const {
964     // isFRMArg has validated the operand, meaning this cast is safe.
965     auto SE = cast<MCSymbolRefExpr>(getImm());
966     RISCVFPRndMode::RoundingMode FRM =
967         RISCVFPRndMode::stringToRoundingMode(SE->getSymbol().getName());
968     assert(FRM != RISCVFPRndMode::Invalid && "Invalid rounding mode");
969     return FRM;
970   }
971 
972   void addFRMArgOperands(MCInst &Inst, unsigned N) const {
973     assert(N == 1 && "Invalid number of operands!");
974     Inst.addOperand(MCOperand::createImm(getRoundingMode()));
975   }
976 };
977 } // end anonymous namespace.
978 
979 #define GET_REGISTER_MATCHER
980 #define GET_SUBTARGET_FEATURE_NAME
981 #define GET_MATCHER_IMPLEMENTATION
982 #define GET_MNEMONIC_SPELL_CHECKER
983 #include "RISCVGenAsmMatcher.inc"
984 
985 static MCRegister convertFPR64ToFPR16(MCRegister Reg) {
986   assert(Reg >= RISCV::F0_D && Reg <= RISCV::F31_D && "Invalid register");
987   return Reg - RISCV::F0_D + RISCV::F0_H;
988 }
989 
990 static MCRegister convertFPR64ToFPR32(MCRegister Reg) {
991   assert(Reg >= RISCV::F0_D && Reg <= RISCV::F31_D && "Invalid register");
992   return Reg - RISCV::F0_D + RISCV::F0_F;
993 }
994 
995 unsigned RISCVAsmParser::validateTargetOperandClass(MCParsedAsmOperand &AsmOp,
996                                                     unsigned Kind) {
997   RISCVOperand &Op = static_cast<RISCVOperand &>(AsmOp);
998   if (!Op.isReg())
999     return Match_InvalidOperand;
1000 
1001   MCRegister Reg = Op.getReg();
1002   bool IsRegFPR64 =
1003       RISCVMCRegisterClasses[RISCV::FPR64RegClassID].contains(Reg);
1004   bool IsRegFPR64C =
1005       RISCVMCRegisterClasses[RISCV::FPR64CRegClassID].contains(Reg);
1006 
1007   // As the parser couldn't differentiate an FPR32 from an FPR64, coerce the
1008   // register from FPR64 to FPR32 or FPR64C to FPR32C if necessary.
1009   if ((IsRegFPR64 && Kind == MCK_FPR32) ||
1010       (IsRegFPR64C && Kind == MCK_FPR32C)) {
1011     Op.Reg.RegNum = convertFPR64ToFPR32(Reg);
1012     return Match_Success;
1013   }
1014   // As the parser couldn't differentiate an FPR16 from an FPR64, coerce the
1015   // register from FPR64 to FPR16 if necessary.
1016   if (IsRegFPR64 && Kind == MCK_FPR16) {
1017     Op.Reg.RegNum = convertFPR64ToFPR16(Reg);
1018     return Match_Success;
1019   }
1020   return Match_InvalidOperand;
1021 }
1022 
1023 bool RISCVAsmParser::generateImmOutOfRangeError(
1024     OperandVector &Operands, uint64_t ErrorInfo, int64_t Lower, int64_t Upper,
1025     Twine Msg = "immediate must be an integer in the range") {
1026   SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1027   return Error(ErrorLoc, Msg + " [" + Twine(Lower) + ", " + Twine(Upper) + "]");
1028 }
1029 
1030 static std::string RISCVMnemonicSpellCheck(StringRef S,
1031                                           const FeatureBitset &FBS,
1032                                           unsigned VariantID = 0);
1033 
1034 bool RISCVAsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
1035                                              OperandVector &Operands,
1036                                              MCStreamer &Out,
1037                                              uint64_t &ErrorInfo,
1038                                              bool MatchingInlineAsm) {
1039   MCInst Inst;
1040   FeatureBitset MissingFeatures;
1041 
1042   auto Result =
1043     MatchInstructionImpl(Operands, Inst, ErrorInfo, MissingFeatures,
1044                          MatchingInlineAsm);
1045   switch (Result) {
1046   default:
1047     break;
1048   case Match_Success:
1049     if (validateInstruction(Inst, Operands))
1050       return true;
1051     return processInstruction(Inst, IDLoc, Operands, Out);
1052   case Match_MissingFeature: {
1053     assert(MissingFeatures.any() && "Unknown missing features!");
1054     bool FirstFeature = true;
1055     std::string Msg = "instruction requires the following:";
1056     for (unsigned i = 0, e = MissingFeatures.size(); i != e; ++i) {
1057       if (MissingFeatures[i]) {
1058         Msg += FirstFeature ? " " : ", ";
1059         Msg += getSubtargetFeatureName(i);
1060         FirstFeature = false;
1061       }
1062     }
1063     return Error(IDLoc, Msg);
1064   }
1065   case Match_MnemonicFail: {
1066     FeatureBitset FBS = ComputeAvailableFeatures(getSTI().getFeatureBits());
1067     std::string Suggestion = RISCVMnemonicSpellCheck(
1068       ((RISCVOperand &)*Operands[0]).getToken(), FBS);
1069     return Error(IDLoc, "unrecognized instruction mnemonic" + Suggestion);
1070   }
1071   case Match_InvalidOperand: {
1072     SMLoc ErrorLoc = IDLoc;
1073     if (ErrorInfo != ~0U) {
1074       if (ErrorInfo >= Operands.size())
1075         return Error(ErrorLoc, "too few operands for instruction");
1076 
1077       ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1078       if (ErrorLoc == SMLoc())
1079         ErrorLoc = IDLoc;
1080     }
1081     return Error(ErrorLoc, "invalid operand for instruction");
1082   }
1083   }
1084 
1085   // Handle the case when the error message is of specific type
1086   // other than the generic Match_InvalidOperand, and the
1087   // corresponding operand is missing.
1088   if (Result > FIRST_TARGET_MATCH_RESULT_TY) {
1089     SMLoc ErrorLoc = IDLoc;
1090     if (ErrorInfo != ~0U && ErrorInfo >= Operands.size())
1091         return Error(ErrorLoc, "too few operands for instruction");
1092   }
1093 
1094   switch(Result) {
1095   default:
1096     break;
1097   case Match_InvalidImmXLenLI:
1098     if (isRV64()) {
1099       SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1100       return Error(ErrorLoc, "operand must be a constant 64-bit integer");
1101     }
1102     return generateImmOutOfRangeError(Operands, ErrorInfo,
1103                                       std::numeric_limits<int32_t>::min(),
1104                                       std::numeric_limits<uint32_t>::max());
1105   case Match_InvalidImmZero: {
1106     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1107     return Error(ErrorLoc, "immediate must be zero");
1108   }
1109   case Match_InvalidUImmLog2XLen:
1110     if (isRV64())
1111       return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 6) - 1);
1112     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1113   case Match_InvalidUImmLog2XLenNonZero:
1114     if (isRV64())
1115       return generateImmOutOfRangeError(Operands, ErrorInfo, 1, (1 << 6) - 1);
1116     return generateImmOutOfRangeError(Operands, ErrorInfo, 1, (1 << 5) - 1);
1117   case Match_InvalidUImmLog2XLenHalf:
1118     if (isRV64())
1119       return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1120     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 4) - 1);
1121   case Match_InvalidUImm5:
1122     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1123   case Match_InvalidSImm6:
1124     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 5),
1125                                       (1 << 5) - 1);
1126   case Match_InvalidSImm6NonZero:
1127     return generateImmOutOfRangeError(
1128         Operands, ErrorInfo, -(1 << 5), (1 << 5) - 1,
1129         "immediate must be non-zero in the range");
1130   case Match_InvalidCLUIImm:
1131     return generateImmOutOfRangeError(
1132         Operands, ErrorInfo, 1, (1 << 5) - 1,
1133         "immediate must be in [0xfffe0, 0xfffff] or");
1134   case Match_InvalidUImm7Lsb00:
1135     return generateImmOutOfRangeError(
1136         Operands, ErrorInfo, 0, (1 << 7) - 4,
1137         "immediate must be a multiple of 4 bytes in the range");
1138   case Match_InvalidUImm8Lsb00:
1139     return generateImmOutOfRangeError(
1140         Operands, ErrorInfo, 0, (1 << 8) - 4,
1141         "immediate must be a multiple of 4 bytes in the range");
1142   case Match_InvalidUImm8Lsb000:
1143     return generateImmOutOfRangeError(
1144         Operands, ErrorInfo, 0, (1 << 8) - 8,
1145         "immediate must be a multiple of 8 bytes in the range");
1146   case Match_InvalidSImm9Lsb0:
1147     return generateImmOutOfRangeError(
1148         Operands, ErrorInfo, -(1 << 8), (1 << 8) - 2,
1149         "immediate must be a multiple of 2 bytes in the range");
1150   case Match_InvalidUImm9Lsb000:
1151     return generateImmOutOfRangeError(
1152         Operands, ErrorInfo, 0, (1 << 9) - 8,
1153         "immediate must be a multiple of 8 bytes in the range");
1154   case Match_InvalidUImm10Lsb00NonZero:
1155     return generateImmOutOfRangeError(
1156         Operands, ErrorInfo, 4, (1 << 10) - 4,
1157         "immediate must be a multiple of 4 bytes in the range");
1158   case Match_InvalidSImm10Lsb0000NonZero:
1159     return generateImmOutOfRangeError(
1160         Operands, ErrorInfo, -(1 << 9), (1 << 9) - 16,
1161         "immediate must be a multiple of 16 bytes and non-zero in the range");
1162   case Match_InvalidSImm12:
1163     return generateImmOutOfRangeError(
1164         Operands, ErrorInfo, -(1 << 11), (1 << 11) - 1,
1165         "operand must be a symbol with %lo/%pcrel_lo/%tprel_lo modifier or an "
1166         "integer in the range");
1167   case Match_InvalidSImm12Lsb0:
1168     return generateImmOutOfRangeError(
1169         Operands, ErrorInfo, -(1 << 11), (1 << 11) - 2,
1170         "immediate must be a multiple of 2 bytes in the range");
1171   case Match_InvalidSImm13Lsb0:
1172     return generateImmOutOfRangeError(
1173         Operands, ErrorInfo, -(1 << 12), (1 << 12) - 2,
1174         "immediate must be a multiple of 2 bytes in the range");
1175   case Match_InvalidUImm20LUI:
1176     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 20) - 1,
1177                                       "operand must be a symbol with "
1178                                       "%hi/%tprel_hi modifier or an integer in "
1179                                       "the range");
1180   case Match_InvalidUImm20AUIPC:
1181     return generateImmOutOfRangeError(
1182         Operands, ErrorInfo, 0, (1 << 20) - 1,
1183         "operand must be a symbol with a "
1184         "%pcrel_hi/%got_pcrel_hi/%tls_ie_pcrel_hi/%tls_gd_pcrel_hi modifier or "
1185         "an integer in the range");
1186   case Match_InvalidSImm21Lsb0JAL:
1187     return generateImmOutOfRangeError(
1188         Operands, ErrorInfo, -(1 << 20), (1 << 20) - 2,
1189         "immediate must be a multiple of 2 bytes in the range");
1190   case Match_InvalidCSRSystemRegister: {
1191     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 12) - 1,
1192                                       "operand must be a valid system register "
1193                                       "name or an integer in the range");
1194   }
1195   case Match_InvalidFenceArg: {
1196     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1197     return Error(
1198         ErrorLoc,
1199         "operand must be formed of letters selected in-order from 'iorw'");
1200   }
1201   case Match_InvalidFRMArg: {
1202     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1203     return Error(
1204         ErrorLoc,
1205         "operand must be a valid floating point rounding mode mnemonic");
1206   }
1207   case Match_InvalidBareSymbol: {
1208     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1209     return Error(ErrorLoc, "operand must be a bare symbol name");
1210   }
1211   case Match_InvalidPseudoJumpSymbol: {
1212     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1213     return Error(ErrorLoc, "operand must be a valid jump target");
1214   }
1215   case Match_InvalidCallSymbol: {
1216     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1217     return Error(ErrorLoc, "operand must be a bare symbol name");
1218   }
1219   case Match_InvalidTPRelAddSymbol: {
1220     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1221     return Error(ErrorLoc, "operand must be a symbol with %tprel_add modifier");
1222   }
1223   case Match_InvalidVTypeI: {
1224     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1225     return Error(
1226         ErrorLoc,
1227         "operand must be "
1228         "e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]");
1229   }
1230   case Match_InvalidVMaskRegister: {
1231     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1232     return Error(ErrorLoc, "operand must be v0.t");
1233   }
1234   case Match_InvalidSImm5Plus1: {
1235     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 4) + 1,
1236                                       (1 << 4),
1237                                       "immediate must be in the range");
1238   }
1239   }
1240 
1241   llvm_unreachable("Unknown match type detected!");
1242 }
1243 
1244 // Attempts to match Name as a register (either using the default name or
1245 // alternative ABI names), setting RegNo to the matching register. Upon
1246 // failure, returns true and sets RegNo to 0. If IsRV32E then registers
1247 // x16-x31 will be rejected.
1248 static bool matchRegisterNameHelper(bool IsRV32E, MCRegister &RegNo,
1249                                     StringRef Name) {
1250   RegNo = MatchRegisterName(Name);
1251   // The 16-/32- and 64-bit FPRs have the same asm name. Check that the initial
1252   // match always matches the 64-bit variant, and not the 16/32-bit one.
1253   assert(!(RegNo >= RISCV::F0_H && RegNo <= RISCV::F31_H));
1254   assert(!(RegNo >= RISCV::F0_F && RegNo <= RISCV::F31_F));
1255   // The default FPR register class is based on the tablegen enum ordering.
1256   static_assert(RISCV::F0_D < RISCV::F0_H, "FPR matching must be updated");
1257   static_assert(RISCV::F0_D < RISCV::F0_F, "FPR matching must be updated");
1258   if (RegNo == RISCV::NoRegister)
1259     RegNo = MatchRegisterAltName(Name);
1260   if (IsRV32E && RegNo >= RISCV::X16 && RegNo <= RISCV::X31)
1261     RegNo = RISCV::NoRegister;
1262   return RegNo == RISCV::NoRegister;
1263 }
1264 
1265 bool RISCVAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
1266                                    SMLoc &EndLoc) {
1267   if (tryParseRegister(RegNo, StartLoc, EndLoc) != MatchOperand_Success)
1268     return Error(StartLoc, "invalid register name");
1269   return false;
1270 }
1271 
1272 OperandMatchResultTy RISCVAsmParser::tryParseRegister(unsigned &RegNo,
1273                                                       SMLoc &StartLoc,
1274                                                       SMLoc &EndLoc) {
1275   const AsmToken &Tok = getParser().getTok();
1276   StartLoc = Tok.getLoc();
1277   EndLoc = Tok.getEndLoc();
1278   RegNo = 0;
1279   StringRef Name = getLexer().getTok().getIdentifier();
1280 
1281   if (matchRegisterNameHelper(isRV32E(), (MCRegister &)RegNo, Name))
1282     return MatchOperand_NoMatch;
1283 
1284   getParser().Lex(); // Eat identifier token.
1285   return MatchOperand_Success;
1286 }
1287 
1288 OperandMatchResultTy RISCVAsmParser::parseRegister(OperandVector &Operands,
1289                                                    bool AllowParens) {
1290   SMLoc FirstS = getLoc();
1291   bool HadParens = false;
1292   AsmToken LParen;
1293 
1294   // If this is an LParen and a parenthesised register name is allowed, parse it
1295   // atomically.
1296   if (AllowParens && getLexer().is(AsmToken::LParen)) {
1297     AsmToken Buf[2];
1298     size_t ReadCount = getLexer().peekTokens(Buf);
1299     if (ReadCount == 2 && Buf[1].getKind() == AsmToken::RParen) {
1300       HadParens = true;
1301       LParen = getParser().getTok();
1302       getParser().Lex(); // Eat '('
1303     }
1304   }
1305 
1306   switch (getLexer().getKind()) {
1307   default:
1308     if (HadParens)
1309       getLexer().UnLex(LParen);
1310     return MatchOperand_NoMatch;
1311   case AsmToken::Identifier:
1312     StringRef Name = getLexer().getTok().getIdentifier();
1313     MCRegister RegNo;
1314     matchRegisterNameHelper(isRV32E(), RegNo, Name);
1315 
1316     if (RegNo == RISCV::NoRegister) {
1317       if (HadParens)
1318         getLexer().UnLex(LParen);
1319       return MatchOperand_NoMatch;
1320     }
1321     if (HadParens)
1322       Operands.push_back(RISCVOperand::createToken("(", FirstS, isRV64()));
1323     SMLoc S = getLoc();
1324     SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1325     getLexer().Lex();
1326     Operands.push_back(RISCVOperand::createReg(RegNo, S, E, isRV64()));
1327   }
1328 
1329   if (HadParens) {
1330     getParser().Lex(); // Eat ')'
1331     Operands.push_back(RISCVOperand::createToken(")", getLoc(), isRV64()));
1332   }
1333 
1334   return MatchOperand_Success;
1335 }
1336 
1337 OperandMatchResultTy
1338 RISCVAsmParser::parseCSRSystemRegister(OperandVector &Operands) {
1339   SMLoc S = getLoc();
1340   const MCExpr *Res;
1341 
1342   switch (getLexer().getKind()) {
1343   default:
1344     return MatchOperand_NoMatch;
1345   case AsmToken::LParen:
1346   case AsmToken::Minus:
1347   case AsmToken::Plus:
1348   case AsmToken::Exclaim:
1349   case AsmToken::Tilde:
1350   case AsmToken::Integer:
1351   case AsmToken::String: {
1352     if (getParser().parseExpression(Res))
1353       return MatchOperand_ParseFail;
1354 
1355     auto *CE = dyn_cast<MCConstantExpr>(Res);
1356     if (CE) {
1357       int64_t Imm = CE->getValue();
1358       if (isUInt<12>(Imm)) {
1359         auto SysReg = RISCVSysReg::lookupSysRegByEncoding(Imm);
1360         // Accept an immediate representing a named or un-named Sys Reg
1361         // if the range is valid, regardless of the required features.
1362         Operands.push_back(RISCVOperand::createSysReg(
1363             SysReg ? SysReg->Name : "", S, Imm, isRV64()));
1364         return MatchOperand_Success;
1365       }
1366     }
1367 
1368     Twine Msg = "immediate must be an integer in the range";
1369     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1370     return MatchOperand_ParseFail;
1371   }
1372   case AsmToken::Identifier: {
1373     StringRef Identifier;
1374     if (getParser().parseIdentifier(Identifier))
1375       return MatchOperand_ParseFail;
1376 
1377     auto SysReg = RISCVSysReg::lookupSysRegByName(Identifier);
1378     if (!SysReg)
1379       SysReg = RISCVSysReg::lookupSysRegByAltName(Identifier);
1380     // Accept a named Sys Reg if the required features are present.
1381     if (SysReg) {
1382       if (!SysReg->haveRequiredFeatures(getSTI().getFeatureBits())) {
1383         Error(S, "system register use requires an option to be enabled");
1384         return MatchOperand_ParseFail;
1385       }
1386       Operands.push_back(RISCVOperand::createSysReg(
1387           Identifier, S, SysReg->Encoding, isRV64()));
1388       return MatchOperand_Success;
1389     }
1390 
1391     Twine Msg = "operand must be a valid system register name "
1392                 "or an integer in the range";
1393     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1394     return MatchOperand_ParseFail;
1395   }
1396   case AsmToken::Percent: {
1397     // Discard operand with modifier.
1398     Twine Msg = "immediate must be an integer in the range";
1399     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1400     return MatchOperand_ParseFail;
1401   }
1402   }
1403 
1404   return MatchOperand_NoMatch;
1405 }
1406 
1407 OperandMatchResultTy RISCVAsmParser::parseImmediate(OperandVector &Operands) {
1408   SMLoc S = getLoc();
1409   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1410   const MCExpr *Res;
1411 
1412   switch (getLexer().getKind()) {
1413   default:
1414     return MatchOperand_NoMatch;
1415   case AsmToken::LParen:
1416   case AsmToken::Dot:
1417   case AsmToken::Minus:
1418   case AsmToken::Plus:
1419   case AsmToken::Exclaim:
1420   case AsmToken::Tilde:
1421   case AsmToken::Integer:
1422   case AsmToken::String:
1423   case AsmToken::Identifier:
1424     if (getParser().parseExpression(Res))
1425       return MatchOperand_ParseFail;
1426     break;
1427   case AsmToken::Percent:
1428     return parseOperandWithModifier(Operands);
1429   }
1430 
1431   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1432   return MatchOperand_Success;
1433 }
1434 
1435 OperandMatchResultTy
1436 RISCVAsmParser::parseOperandWithModifier(OperandVector &Operands) {
1437   SMLoc S = getLoc();
1438   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1439 
1440   if (getLexer().getKind() != AsmToken::Percent) {
1441     Error(getLoc(), "expected '%' for operand modifier");
1442     return MatchOperand_ParseFail;
1443   }
1444 
1445   getParser().Lex(); // Eat '%'
1446 
1447   if (getLexer().getKind() != AsmToken::Identifier) {
1448     Error(getLoc(), "expected valid identifier for operand modifier");
1449     return MatchOperand_ParseFail;
1450   }
1451   StringRef Identifier = getParser().getTok().getIdentifier();
1452   RISCVMCExpr::VariantKind VK = RISCVMCExpr::getVariantKindForName(Identifier);
1453   if (VK == RISCVMCExpr::VK_RISCV_Invalid) {
1454     Error(getLoc(), "unrecognized operand modifier");
1455     return MatchOperand_ParseFail;
1456   }
1457 
1458   getParser().Lex(); // Eat the identifier
1459   if (getLexer().getKind() != AsmToken::LParen) {
1460     Error(getLoc(), "expected '('");
1461     return MatchOperand_ParseFail;
1462   }
1463   getParser().Lex(); // Eat '('
1464 
1465   const MCExpr *SubExpr;
1466   if (getParser().parseParenExpression(SubExpr, E)) {
1467     return MatchOperand_ParseFail;
1468   }
1469 
1470   const MCExpr *ModExpr = RISCVMCExpr::create(SubExpr, VK, getContext());
1471   Operands.push_back(RISCVOperand::createImm(ModExpr, S, E, isRV64()));
1472   return MatchOperand_Success;
1473 }
1474 
1475 OperandMatchResultTy RISCVAsmParser::parseBareSymbol(OperandVector &Operands) {
1476   SMLoc S = getLoc();
1477   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1478   const MCExpr *Res;
1479 
1480   if (getLexer().getKind() != AsmToken::Identifier)
1481     return MatchOperand_NoMatch;
1482 
1483   StringRef Identifier;
1484   AsmToken Tok = getLexer().getTok();
1485 
1486   if (getParser().parseIdentifier(Identifier))
1487     return MatchOperand_ParseFail;
1488 
1489   if (Identifier.consume_back("@plt")) {
1490     Error(getLoc(), "'@plt' operand not valid for instruction");
1491     return MatchOperand_ParseFail;
1492   }
1493 
1494   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
1495 
1496   if (Sym->isVariable()) {
1497     const MCExpr *V = Sym->getVariableValue(/*SetUsed=*/false);
1498     if (!isa<MCSymbolRefExpr>(V)) {
1499       getLexer().UnLex(Tok); // Put back if it's not a bare symbol.
1500       return MatchOperand_NoMatch;
1501     }
1502     Res = V;
1503   } else
1504     Res = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
1505 
1506   MCBinaryExpr::Opcode Opcode;
1507   switch (getLexer().getKind()) {
1508   default:
1509     Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1510     return MatchOperand_Success;
1511   case AsmToken::Plus:
1512     Opcode = MCBinaryExpr::Add;
1513     break;
1514   case AsmToken::Minus:
1515     Opcode = MCBinaryExpr::Sub;
1516     break;
1517   }
1518 
1519   const MCExpr *Expr;
1520   if (getParser().parseExpression(Expr))
1521     return MatchOperand_ParseFail;
1522   Res = MCBinaryExpr::create(Opcode, Res, Expr, getContext());
1523   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1524   return MatchOperand_Success;
1525 }
1526 
1527 OperandMatchResultTy RISCVAsmParser::parseCallSymbol(OperandVector &Operands) {
1528   SMLoc S = getLoc();
1529   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1530   const MCExpr *Res;
1531 
1532   if (getLexer().getKind() != AsmToken::Identifier)
1533     return MatchOperand_NoMatch;
1534 
1535   // Avoid parsing the register in `call rd, foo` as a call symbol.
1536   if (getLexer().peekTok().getKind() != AsmToken::EndOfStatement)
1537     return MatchOperand_NoMatch;
1538 
1539   StringRef Identifier;
1540   if (getParser().parseIdentifier(Identifier))
1541     return MatchOperand_ParseFail;
1542 
1543   RISCVMCExpr::VariantKind Kind = RISCVMCExpr::VK_RISCV_CALL;
1544   if (Identifier.consume_back("@plt"))
1545     Kind = RISCVMCExpr::VK_RISCV_CALL_PLT;
1546 
1547   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
1548   Res = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
1549   Res = RISCVMCExpr::create(Res, Kind, getContext());
1550   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1551   return MatchOperand_Success;
1552 }
1553 
1554 OperandMatchResultTy
1555 RISCVAsmParser::parsePseudoJumpSymbol(OperandVector &Operands) {
1556   SMLoc S = getLoc();
1557   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1558   const MCExpr *Res;
1559 
1560   if (getParser().parseExpression(Res))
1561     return MatchOperand_ParseFail;
1562 
1563   if (Res->getKind() != MCExpr::ExprKind::SymbolRef ||
1564       cast<MCSymbolRefExpr>(Res)->getKind() ==
1565           MCSymbolRefExpr::VariantKind::VK_PLT) {
1566     Error(S, "operand must be a valid jump target");
1567     return MatchOperand_ParseFail;
1568   }
1569 
1570   Res = RISCVMCExpr::create(Res, RISCVMCExpr::VK_RISCV_CALL, getContext());
1571   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1572   return MatchOperand_Success;
1573 }
1574 
1575 OperandMatchResultTy RISCVAsmParser::parseJALOffset(OperandVector &Operands) {
1576   // Parsing jal operands is fiddly due to the `jal foo` and `jal ra, foo`
1577   // both being acceptable forms. When parsing `jal ra, foo` this function
1578   // will be called for the `ra` register operand in an attempt to match the
1579   // single-operand alias. parseJALOffset must fail for this case. It would
1580   // seem logical to try parse the operand using parseImmediate and return
1581   // NoMatch if the next token is a comma (meaning we must be parsing a jal in
1582   // the second form rather than the first). We can't do this as there's no
1583   // way of rewinding the lexer state. Instead, return NoMatch if this operand
1584   // is an identifier and is followed by a comma.
1585   if (getLexer().is(AsmToken::Identifier) &&
1586       getLexer().peekTok().is(AsmToken::Comma))
1587     return MatchOperand_NoMatch;
1588 
1589   return parseImmediate(Operands);
1590 }
1591 
1592 OperandMatchResultTy RISCVAsmParser::parseVTypeI(OperandVector &Operands) {
1593   SMLoc S = getLoc();
1594   if (getLexer().getKind() != AsmToken::Identifier)
1595     return MatchOperand_NoMatch;
1596 
1597   // Parse "e8,m1,t[a|u],m[a|u]"
1598   StringRef Name = getLexer().getTok().getIdentifier();
1599   if (!Name.consume_front("e"))
1600     return MatchOperand_NoMatch;
1601   APInt Sew(16, Name, 10);
1602   if (Sew != 8 && Sew != 16 && Sew != 32 && Sew != 64 && Sew != 128 &&
1603       Sew != 256 && Sew != 512 && Sew != 1024)
1604     return MatchOperand_NoMatch;
1605   getLexer().Lex();
1606 
1607   if (!getLexer().is(AsmToken::Comma))
1608     return MatchOperand_NoMatch;
1609   getLexer().Lex();
1610 
1611   Name = getLexer().getTok().getIdentifier();
1612   if (!Name.consume_front("m"))
1613     return MatchOperand_NoMatch;
1614   // "m" or "mf"
1615   bool Fractional = false;
1616   if (Name.consume_front("f")) {
1617     Fractional = true;
1618   }
1619   APInt Lmul(16, Name, 10);
1620   if (Lmul != 1 && Lmul != 2 && Lmul != 4 && Lmul != 8)
1621     return MatchOperand_NoMatch;
1622   getLexer().Lex();
1623 
1624   if (!getLexer().is(AsmToken::Comma))
1625     return MatchOperand_NoMatch;
1626   getLexer().Lex();
1627 
1628   Name = getLexer().getTok().getIdentifier();
1629   // ta or tu
1630   bool TailAgnostic;
1631   if (Name.consume_front("ta"))
1632     TailAgnostic = true;
1633   else if (Name.consume_front("tu"))
1634     TailAgnostic = false;
1635   else
1636     return MatchOperand_NoMatch;
1637   getLexer().Lex();
1638 
1639   if (!getLexer().is(AsmToken::Comma))
1640     return MatchOperand_NoMatch;
1641   getLexer().Lex();
1642 
1643   Name = getLexer().getTok().getIdentifier();
1644   // ma or mu
1645   bool MaskedoffAgnostic;
1646   if (Name.consume_front("ma"))
1647     MaskedoffAgnostic = true;
1648   else if (Name.consume_front("mu"))
1649     MaskedoffAgnostic = false;
1650   else
1651     return MatchOperand_NoMatch;
1652   getLexer().Lex();
1653 
1654   if (getLexer().getKind() != AsmToken::EndOfStatement)
1655     return MatchOperand_NoMatch;
1656 
1657   Operands.push_back(RISCVOperand::createVType(
1658       Sew, Lmul, Fractional, TailAgnostic, MaskedoffAgnostic, S, isRV64()));
1659 
1660   return MatchOperand_Success;
1661 }
1662 
1663 OperandMatchResultTy RISCVAsmParser::parseMaskReg(OperandVector &Operands) {
1664   switch (getLexer().getKind()) {
1665   default:
1666     return MatchOperand_NoMatch;
1667   case AsmToken::Identifier:
1668     StringRef Name = getLexer().getTok().getIdentifier();
1669     if (!Name.consume_back(".t")) {
1670       Error(getLoc(), "expected '.t' suffix");
1671       return MatchOperand_ParseFail;
1672     }
1673     MCRegister RegNo;
1674     matchRegisterNameHelper(isRV32E(), RegNo, Name);
1675 
1676     if (RegNo == RISCV::NoRegister)
1677       return MatchOperand_NoMatch;
1678     if (RegNo != RISCV::V0)
1679       return MatchOperand_NoMatch;
1680     SMLoc S = getLoc();
1681     SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1682     getLexer().Lex();
1683     Operands.push_back(RISCVOperand::createReg(RegNo, S, E, isRV64()));
1684   }
1685 
1686   return MatchOperand_Success;
1687 }
1688 
1689 OperandMatchResultTy
1690 RISCVAsmParser::parseMemOpBaseReg(OperandVector &Operands) {
1691   if (getLexer().isNot(AsmToken::LParen)) {
1692     Error(getLoc(), "expected '('");
1693     return MatchOperand_ParseFail;
1694   }
1695 
1696   getParser().Lex(); // Eat '('
1697   Operands.push_back(RISCVOperand::createToken("(", getLoc(), isRV64()));
1698 
1699   if (parseRegister(Operands) != MatchOperand_Success) {
1700     Error(getLoc(), "expected register");
1701     return MatchOperand_ParseFail;
1702   }
1703 
1704   if (getLexer().isNot(AsmToken::RParen)) {
1705     Error(getLoc(), "expected ')'");
1706     return MatchOperand_ParseFail;
1707   }
1708 
1709   getParser().Lex(); // Eat ')'
1710   Operands.push_back(RISCVOperand::createToken(")", getLoc(), isRV64()));
1711 
1712   return MatchOperand_Success;
1713 }
1714 
1715 OperandMatchResultTy RISCVAsmParser::parseAtomicMemOp(OperandVector &Operands) {
1716   // Atomic operations such as lr.w, sc.w, and amo*.w accept a "memory operand"
1717   // as one of their register operands, such as `(a0)`. This just denotes that
1718   // the register (in this case `a0`) contains a memory address.
1719   //
1720   // Normally, we would be able to parse these by putting the parens into the
1721   // instruction string. However, GNU as also accepts a zero-offset memory
1722   // operand (such as `0(a0)`), and ignores the 0. Normally this would be parsed
1723   // with parseImmediate followed by parseMemOpBaseReg, but these instructions
1724   // do not accept an immediate operand, and we do not want to add a "dummy"
1725   // operand that is silently dropped.
1726   //
1727   // Instead, we use this custom parser. This will: allow (and discard) an
1728   // offset if it is zero; require (and discard) parentheses; and add only the
1729   // parsed register operand to `Operands`.
1730   //
1731   // These operands are printed with RISCVInstPrinter::printAtomicMemOp, which
1732   // will only print the register surrounded by parentheses (which GNU as also
1733   // uses as its canonical representation for these operands).
1734   std::unique_ptr<RISCVOperand> OptionalImmOp;
1735 
1736   if (getLexer().isNot(AsmToken::LParen)) {
1737     // Parse an Integer token. We do not accept arbritrary constant expressions
1738     // in the offset field (because they may include parens, which complicates
1739     // parsing a lot).
1740     int64_t ImmVal;
1741     SMLoc ImmStart = getLoc();
1742     if (getParser().parseIntToken(ImmVal,
1743                                   "expected '(' or optional integer offset"))
1744       return MatchOperand_ParseFail;
1745 
1746     // Create a RISCVOperand for checking later (so the error messages are
1747     // nicer), but we don't add it to Operands.
1748     SMLoc ImmEnd = getLoc();
1749     OptionalImmOp =
1750         RISCVOperand::createImm(MCConstantExpr::create(ImmVal, getContext()),
1751                                 ImmStart, ImmEnd, isRV64());
1752   }
1753 
1754   if (getLexer().isNot(AsmToken::LParen)) {
1755     Error(getLoc(), OptionalImmOp ? "expected '(' after optional integer offset"
1756                                   : "expected '(' or optional integer offset");
1757     return MatchOperand_ParseFail;
1758   }
1759   getParser().Lex(); // Eat '('
1760 
1761   if (parseRegister(Operands) != MatchOperand_Success) {
1762     Error(getLoc(), "expected register");
1763     return MatchOperand_ParseFail;
1764   }
1765 
1766   if (getLexer().isNot(AsmToken::RParen)) {
1767     Error(getLoc(), "expected ')'");
1768     return MatchOperand_ParseFail;
1769   }
1770   getParser().Lex(); // Eat ')'
1771 
1772   // Deferred Handling of non-zero offsets. This makes the error messages nicer.
1773   if (OptionalImmOp && !OptionalImmOp->isImmZero()) {
1774     Error(OptionalImmOp->getStartLoc(), "optional integer offset must be 0",
1775           SMRange(OptionalImmOp->getStartLoc(), OptionalImmOp->getEndLoc()));
1776     return MatchOperand_ParseFail;
1777   }
1778 
1779   return MatchOperand_Success;
1780 }
1781 
1782 /// Looks at a token type and creates the relevant operand from this
1783 /// information, adding to Operands. If operand was parsed, returns false, else
1784 /// true.
1785 bool RISCVAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) {
1786   // Check if the current operand has a custom associated parser, if so, try to
1787   // custom parse the operand, or fallback to the general approach.
1788   OperandMatchResultTy Result =
1789       MatchOperandParserImpl(Operands, Mnemonic, /*ParseForAllFeatures=*/true);
1790   if (Result == MatchOperand_Success)
1791     return false;
1792   if (Result == MatchOperand_ParseFail)
1793     return true;
1794 
1795   // Attempt to parse token as a register.
1796   if (parseRegister(Operands, true) == MatchOperand_Success)
1797     return false;
1798 
1799   // Attempt to parse token as an immediate
1800   if (parseImmediate(Operands) == MatchOperand_Success) {
1801     // Parse memory base register if present
1802     if (getLexer().is(AsmToken::LParen))
1803       return parseMemOpBaseReg(Operands) != MatchOperand_Success;
1804     return false;
1805   }
1806 
1807   // Finally we have exhausted all options and must declare defeat.
1808   Error(getLoc(), "unknown operand");
1809   return true;
1810 }
1811 
1812 bool RISCVAsmParser::ParseInstruction(ParseInstructionInfo &Info,
1813                                       StringRef Name, SMLoc NameLoc,
1814                                       OperandVector &Operands) {
1815   // Ensure that if the instruction occurs when relaxation is enabled,
1816   // relocations are forced for the file. Ideally this would be done when there
1817   // is enough information to reliably determine if the instruction itself may
1818   // cause relaxations. Unfortunately instruction processing stage occurs in the
1819   // same pass as relocation emission, so it's too late to set a 'sticky bit'
1820   // for the entire file.
1821   if (getSTI().getFeatureBits()[RISCV::FeatureRelax]) {
1822     auto *Assembler = getTargetStreamer().getStreamer().getAssemblerPtr();
1823     if (Assembler != nullptr) {
1824       RISCVAsmBackend &MAB =
1825           static_cast<RISCVAsmBackend &>(Assembler->getBackend());
1826       MAB.setForceRelocs();
1827     }
1828   }
1829 
1830   // First operand is token for instruction
1831   Operands.push_back(RISCVOperand::createToken(Name, NameLoc, isRV64()));
1832 
1833   // If there are no more operands, then finish
1834   if (getLexer().is(AsmToken::EndOfStatement))
1835     return false;
1836 
1837   // Parse first operand
1838   if (parseOperand(Operands, Name))
1839     return true;
1840 
1841   // Parse until end of statement, consuming commas between operands
1842   unsigned OperandIdx = 1;
1843   while (getLexer().is(AsmToken::Comma)) {
1844     // Consume comma token
1845     getLexer().Lex();
1846 
1847     // Parse next operand
1848     if (parseOperand(Operands, Name))
1849       return true;
1850 
1851     ++OperandIdx;
1852   }
1853 
1854   if (getLexer().isNot(AsmToken::EndOfStatement)) {
1855     SMLoc Loc = getLexer().getLoc();
1856     getParser().eatToEndOfStatement();
1857     return Error(Loc, "unexpected token");
1858   }
1859 
1860   getParser().Lex(); // Consume the EndOfStatement.
1861   return false;
1862 }
1863 
1864 bool RISCVAsmParser::classifySymbolRef(const MCExpr *Expr,
1865                                        RISCVMCExpr::VariantKind &Kind) {
1866   Kind = RISCVMCExpr::VK_RISCV_None;
1867 
1868   if (const RISCVMCExpr *RE = dyn_cast<RISCVMCExpr>(Expr)) {
1869     Kind = RE->getKind();
1870     Expr = RE->getSubExpr();
1871   }
1872 
1873   MCValue Res;
1874   MCFixup Fixup;
1875   if (Expr->evaluateAsRelocatable(Res, nullptr, &Fixup))
1876     return Res.getRefKind() == RISCVMCExpr::VK_RISCV_None;
1877   return false;
1878 }
1879 
1880 bool RISCVAsmParser::ParseDirective(AsmToken DirectiveID) {
1881   // This returns false if this function recognizes the directive
1882   // regardless of whether it is successfully handles or reports an
1883   // error. Otherwise it returns true to give the generic parser a
1884   // chance at recognizing it.
1885   StringRef IDVal = DirectiveID.getString();
1886 
1887   if (IDVal == ".option")
1888     return parseDirectiveOption();
1889   else if (IDVal == ".attribute")
1890     return parseDirectiveAttribute();
1891 
1892   return true;
1893 }
1894 
1895 bool RISCVAsmParser::parseDirectiveOption() {
1896   MCAsmParser &Parser = getParser();
1897   // Get the option token.
1898   AsmToken Tok = Parser.getTok();
1899   // At the moment only identifiers are supported.
1900   if (Tok.isNot(AsmToken::Identifier))
1901     return Error(Parser.getTok().getLoc(),
1902                  "unexpected token, expected identifier");
1903 
1904   StringRef Option = Tok.getIdentifier();
1905 
1906   if (Option == "push") {
1907     getTargetStreamer().emitDirectiveOptionPush();
1908 
1909     Parser.Lex();
1910     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1911       return Error(Parser.getTok().getLoc(),
1912                    "unexpected token, expected end of statement");
1913 
1914     pushFeatureBits();
1915     return false;
1916   }
1917 
1918   if (Option == "pop") {
1919     SMLoc StartLoc = Parser.getTok().getLoc();
1920     getTargetStreamer().emitDirectiveOptionPop();
1921 
1922     Parser.Lex();
1923     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1924       return Error(Parser.getTok().getLoc(),
1925                    "unexpected token, expected end of statement");
1926 
1927     if (popFeatureBits())
1928       return Error(StartLoc, ".option pop with no .option push");
1929 
1930     return false;
1931   }
1932 
1933   if (Option == "rvc") {
1934     getTargetStreamer().emitDirectiveOptionRVC();
1935 
1936     Parser.Lex();
1937     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1938       return Error(Parser.getTok().getLoc(),
1939                    "unexpected token, expected end of statement");
1940 
1941     setFeatureBits(RISCV::FeatureStdExtC, "c");
1942     return false;
1943   }
1944 
1945   if (Option == "norvc") {
1946     getTargetStreamer().emitDirectiveOptionNoRVC();
1947 
1948     Parser.Lex();
1949     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1950       return Error(Parser.getTok().getLoc(),
1951                    "unexpected token, expected end of statement");
1952 
1953     clearFeatureBits(RISCV::FeatureStdExtC, "c");
1954     return false;
1955   }
1956 
1957   if (Option == "pic") {
1958     getTargetStreamer().emitDirectiveOptionPIC();
1959 
1960     Parser.Lex();
1961     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1962       return Error(Parser.getTok().getLoc(),
1963                    "unexpected token, expected end of statement");
1964 
1965     ParserOptions.IsPicEnabled = true;
1966     return false;
1967   }
1968 
1969   if (Option == "nopic") {
1970     getTargetStreamer().emitDirectiveOptionNoPIC();
1971 
1972     Parser.Lex();
1973     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1974       return Error(Parser.getTok().getLoc(),
1975                    "unexpected token, expected end of statement");
1976 
1977     ParserOptions.IsPicEnabled = false;
1978     return false;
1979   }
1980 
1981   if (Option == "relax") {
1982     getTargetStreamer().emitDirectiveOptionRelax();
1983 
1984     Parser.Lex();
1985     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1986       return Error(Parser.getTok().getLoc(),
1987                    "unexpected token, expected end of statement");
1988 
1989     setFeatureBits(RISCV::FeatureRelax, "relax");
1990     return false;
1991   }
1992 
1993   if (Option == "norelax") {
1994     getTargetStreamer().emitDirectiveOptionNoRelax();
1995 
1996     Parser.Lex();
1997     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1998       return Error(Parser.getTok().getLoc(),
1999                    "unexpected token, expected end of statement");
2000 
2001     clearFeatureBits(RISCV::FeatureRelax, "relax");
2002     return false;
2003   }
2004 
2005   // Unknown option.
2006   Warning(Parser.getTok().getLoc(),
2007           "unknown option, expected 'push', 'pop', 'rvc', 'norvc', 'relax' or "
2008           "'norelax'");
2009   Parser.eatToEndOfStatement();
2010   return false;
2011 }
2012 
2013 /// parseDirectiveAttribute
2014 ///  ::= .attribute expression ',' ( expression | "string" )
2015 ///  ::= .attribute identifier ',' ( expression | "string" )
2016 bool RISCVAsmParser::parseDirectiveAttribute() {
2017   MCAsmParser &Parser = getParser();
2018   int64_t Tag;
2019   SMLoc TagLoc;
2020   TagLoc = Parser.getTok().getLoc();
2021   if (Parser.getTok().is(AsmToken::Identifier)) {
2022     StringRef Name = Parser.getTok().getIdentifier();
2023     Optional<unsigned> Ret =
2024         ELFAttrs::attrTypeFromString(Name, RISCVAttrs::RISCVAttributeTags);
2025     if (!Ret.hasValue()) {
2026       Error(TagLoc, "attribute name not recognised: " + Name);
2027       return false;
2028     }
2029     Tag = Ret.getValue();
2030     Parser.Lex();
2031   } else {
2032     const MCExpr *AttrExpr;
2033 
2034     TagLoc = Parser.getTok().getLoc();
2035     if (Parser.parseExpression(AttrExpr))
2036       return true;
2037 
2038     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(AttrExpr);
2039     if (check(!CE, TagLoc, "expected numeric constant"))
2040       return true;
2041 
2042     Tag = CE->getValue();
2043   }
2044 
2045   if (Parser.parseToken(AsmToken::Comma, "comma expected"))
2046     return true;
2047 
2048   StringRef StringValue;
2049   int64_t IntegerValue = 0;
2050   bool IsIntegerValue = true;
2051 
2052   // RISC-V attributes have a string value if the tag number is odd
2053   // and an integer value if the tag number is even.
2054   if (Tag % 2)
2055     IsIntegerValue = false;
2056 
2057   SMLoc ValueExprLoc = Parser.getTok().getLoc();
2058   if (IsIntegerValue) {
2059     const MCExpr *ValueExpr;
2060     if (Parser.parseExpression(ValueExpr))
2061       return true;
2062 
2063     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(ValueExpr);
2064     if (!CE)
2065       return Error(ValueExprLoc, "expected numeric constant");
2066     IntegerValue = CE->getValue();
2067   } else {
2068     if (Parser.getTok().isNot(AsmToken::String))
2069       return Error(Parser.getTok().getLoc(), "expected string constant");
2070 
2071     StringValue = Parser.getTok().getStringContents();
2072     Parser.Lex();
2073   }
2074 
2075   if (Parser.parseToken(AsmToken::EndOfStatement,
2076                         "unexpected token in '.attribute' directive"))
2077     return true;
2078 
2079   if (Tag == RISCVAttrs::ARCH) {
2080     StringRef Arch = StringValue;
2081     if (Arch.consume_front("rv32"))
2082       clearFeatureBits(RISCV::Feature64Bit, "64bit");
2083     else if (Arch.consume_front("rv64"))
2084       setFeatureBits(RISCV::Feature64Bit, "64bit");
2085     else
2086       return Error(ValueExprLoc, "bad arch string " + Arch);
2087 
2088     while (!Arch.empty()) {
2089       if (Arch[0] == 'i')
2090         clearFeatureBits(RISCV::FeatureRV32E, "e");
2091       else if (Arch[0] == 'e')
2092         setFeatureBits(RISCV::FeatureRV32E, "e");
2093       else if (Arch[0] == 'g') {
2094         clearFeatureBits(RISCV::FeatureRV32E, "e");
2095         setFeatureBits(RISCV::FeatureStdExtM, "m");
2096         setFeatureBits(RISCV::FeatureStdExtA, "a");
2097         setFeatureBits(RISCV::FeatureStdExtF, "f");
2098         setFeatureBits(RISCV::FeatureStdExtD, "d");
2099       } else if (Arch[0] == 'm')
2100         setFeatureBits(RISCV::FeatureStdExtM, "m");
2101       else if (Arch[0] == 'a')
2102         setFeatureBits(RISCV::FeatureStdExtA, "a");
2103       else if (Arch[0] == 'f')
2104         setFeatureBits(RISCV::FeatureStdExtF, "f");
2105       else if (Arch[0] == 'd') {
2106         setFeatureBits(RISCV::FeatureStdExtF, "f");
2107         setFeatureBits(RISCV::FeatureStdExtD, "d");
2108       } else if (Arch[0] == 'c') {
2109         setFeatureBits(RISCV::FeatureStdExtC, "c");
2110       } else
2111         return Error(ValueExprLoc, "bad arch string " + Arch);
2112 
2113       Arch = Arch.drop_front(1);
2114       int major = 0;
2115       int minor = 0;
2116       Arch.consumeInteger(10, major);
2117       Arch.consume_front("p");
2118       Arch.consumeInteger(10, minor);
2119       if (major != 0 || minor != 0) {
2120         Arch = Arch.drop_until([](char c) { return c == '_' || c == '"'; });
2121         Arch = Arch.drop_while([](char c) { return c == '_'; });
2122       }
2123     }
2124   }
2125 
2126   if (IsIntegerValue)
2127     getTargetStreamer().emitAttribute(Tag, IntegerValue);
2128   else {
2129     if (Tag != RISCVAttrs::ARCH) {
2130       getTargetStreamer().emitTextAttribute(Tag, StringValue);
2131     } else {
2132       std::string formalArchStr = "rv32";
2133       if (getFeatureBits(RISCV::Feature64Bit))
2134         formalArchStr = "rv64";
2135       if (getFeatureBits(RISCV::FeatureRV32E))
2136         formalArchStr = (Twine(formalArchStr) + "e1p9").str();
2137       else
2138         formalArchStr = (Twine(formalArchStr) + "i2p0").str();
2139 
2140       if (getFeatureBits(RISCV::FeatureStdExtM))
2141         formalArchStr = (Twine(formalArchStr) + "_m2p0").str();
2142       if (getFeatureBits(RISCV::FeatureStdExtA))
2143         formalArchStr = (Twine(formalArchStr) + "_a2p0").str();
2144       if (getFeatureBits(RISCV::FeatureStdExtF))
2145         formalArchStr = (Twine(formalArchStr) + "_f2p0").str();
2146       if (getFeatureBits(RISCV::FeatureStdExtD))
2147         formalArchStr = (Twine(formalArchStr) + "_d2p0").str();
2148       if (getFeatureBits(RISCV::FeatureStdExtC))
2149         formalArchStr = (Twine(formalArchStr) + "_c2p0").str();
2150 
2151       getTargetStreamer().emitTextAttribute(Tag, formalArchStr);
2152     }
2153   }
2154 
2155   return false;
2156 }
2157 
2158 void RISCVAsmParser::emitToStreamer(MCStreamer &S, const MCInst &Inst) {
2159   MCInst CInst;
2160   bool Res = compressInst(CInst, Inst, getSTI(), S.getContext());
2161   if (Res)
2162     ++RISCVNumInstrsCompressed;
2163   S.emitInstruction((Res ? CInst : Inst), getSTI());
2164 }
2165 
2166 void RISCVAsmParser::emitLoadImm(MCRegister DestReg, int64_t Value,
2167                                  MCStreamer &Out) {
2168   RISCVMatInt::InstSeq Seq;
2169   RISCVMatInt::generateInstSeq(Value, isRV64(), Seq);
2170 
2171   MCRegister SrcReg = RISCV::X0;
2172   for (RISCVMatInt::Inst &Inst : Seq) {
2173     if (Inst.Opc == RISCV::LUI) {
2174       emitToStreamer(
2175           Out, MCInstBuilder(RISCV::LUI).addReg(DestReg).addImm(Inst.Imm));
2176     } else {
2177       emitToStreamer(
2178           Out, MCInstBuilder(Inst.Opc).addReg(DestReg).addReg(SrcReg).addImm(
2179                    Inst.Imm));
2180     }
2181 
2182     // Only the first instruction has X0 as its source.
2183     SrcReg = DestReg;
2184   }
2185 }
2186 
2187 void RISCVAsmParser::emitAuipcInstPair(MCOperand DestReg, MCOperand TmpReg,
2188                                        const MCExpr *Symbol,
2189                                        RISCVMCExpr::VariantKind VKHi,
2190                                        unsigned SecondOpcode, SMLoc IDLoc,
2191                                        MCStreamer &Out) {
2192   // A pair of instructions for PC-relative addressing; expands to
2193   //   TmpLabel: AUIPC TmpReg, VKHi(symbol)
2194   //             OP DestReg, TmpReg, %pcrel_lo(TmpLabel)
2195   MCContext &Ctx = getContext();
2196 
2197   MCSymbol *TmpLabel = Ctx.createTempSymbol(
2198       "pcrel_hi", /* AlwaysAddSuffix */ true, /* CanBeUnnamed */ false);
2199   Out.emitLabel(TmpLabel);
2200 
2201   const RISCVMCExpr *SymbolHi = RISCVMCExpr::create(Symbol, VKHi, Ctx);
2202   emitToStreamer(
2203       Out, MCInstBuilder(RISCV::AUIPC).addOperand(TmpReg).addExpr(SymbolHi));
2204 
2205   const MCExpr *RefToLinkTmpLabel =
2206       RISCVMCExpr::create(MCSymbolRefExpr::create(TmpLabel, Ctx),
2207                           RISCVMCExpr::VK_RISCV_PCREL_LO, Ctx);
2208 
2209   emitToStreamer(Out, MCInstBuilder(SecondOpcode)
2210                           .addOperand(DestReg)
2211                           .addOperand(TmpReg)
2212                           .addExpr(RefToLinkTmpLabel));
2213 }
2214 
2215 void RISCVAsmParser::emitLoadLocalAddress(MCInst &Inst, SMLoc IDLoc,
2216                                           MCStreamer &Out) {
2217   // The load local address pseudo-instruction "lla" is used in PC-relative
2218   // addressing of local symbols:
2219   //   lla rdest, symbol
2220   // expands to
2221   //   TmpLabel: AUIPC rdest, %pcrel_hi(symbol)
2222   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2223   MCOperand DestReg = Inst.getOperand(0);
2224   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2225   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_PCREL_HI,
2226                     RISCV::ADDI, IDLoc, Out);
2227 }
2228 
2229 void RISCVAsmParser::emitLoadAddress(MCInst &Inst, SMLoc IDLoc,
2230                                      MCStreamer &Out) {
2231   // The load address pseudo-instruction "la" is used in PC-relative and
2232   // GOT-indirect addressing of global symbols:
2233   //   la rdest, symbol
2234   // expands to either (for non-PIC)
2235   //   TmpLabel: AUIPC rdest, %pcrel_hi(symbol)
2236   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2237   // or (for PIC)
2238   //   TmpLabel: AUIPC rdest, %got_pcrel_hi(symbol)
2239   //             Lx rdest, %pcrel_lo(TmpLabel)(rdest)
2240   MCOperand DestReg = Inst.getOperand(0);
2241   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2242   unsigned SecondOpcode;
2243   RISCVMCExpr::VariantKind VKHi;
2244   if (ParserOptions.IsPicEnabled) {
2245     SecondOpcode = isRV64() ? RISCV::LD : RISCV::LW;
2246     VKHi = RISCVMCExpr::VK_RISCV_GOT_HI;
2247   } else {
2248     SecondOpcode = RISCV::ADDI;
2249     VKHi = RISCVMCExpr::VK_RISCV_PCREL_HI;
2250   }
2251   emitAuipcInstPair(DestReg, DestReg, Symbol, VKHi, SecondOpcode, IDLoc, Out);
2252 }
2253 
2254 void RISCVAsmParser::emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc,
2255                                           MCStreamer &Out) {
2256   // The load TLS IE address pseudo-instruction "la.tls.ie" is used in
2257   // initial-exec TLS model addressing of global symbols:
2258   //   la.tls.ie rdest, symbol
2259   // expands to
2260   //   TmpLabel: AUIPC rdest, %tls_ie_pcrel_hi(symbol)
2261   //             Lx rdest, %pcrel_lo(TmpLabel)(rdest)
2262   MCOperand DestReg = Inst.getOperand(0);
2263   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2264   unsigned SecondOpcode = isRV64() ? RISCV::LD : RISCV::LW;
2265   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GOT_HI,
2266                     SecondOpcode, IDLoc, Out);
2267 }
2268 
2269 void RISCVAsmParser::emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc,
2270                                           MCStreamer &Out) {
2271   // The load TLS GD address pseudo-instruction "la.tls.gd" is used in
2272   // global-dynamic TLS model addressing of global symbols:
2273   //   la.tls.gd rdest, symbol
2274   // expands to
2275   //   TmpLabel: AUIPC rdest, %tls_gd_pcrel_hi(symbol)
2276   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2277   MCOperand DestReg = Inst.getOperand(0);
2278   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2279   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GD_HI,
2280                     RISCV::ADDI, IDLoc, Out);
2281 }
2282 
2283 void RISCVAsmParser::emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode,
2284                                          SMLoc IDLoc, MCStreamer &Out,
2285                                          bool HasTmpReg) {
2286   // The load/store pseudo-instruction does a pc-relative load with
2287   // a symbol.
2288   //
2289   // The expansion looks like this
2290   //
2291   //   TmpLabel: AUIPC tmp, %pcrel_hi(symbol)
2292   //             [S|L]X    rd, %pcrel_lo(TmpLabel)(tmp)
2293   MCOperand DestReg = Inst.getOperand(0);
2294   unsigned SymbolOpIdx = HasTmpReg ? 2 : 1;
2295   unsigned TmpRegOpIdx = HasTmpReg ? 1 : 0;
2296   MCOperand TmpReg = Inst.getOperand(TmpRegOpIdx);
2297   const MCExpr *Symbol = Inst.getOperand(SymbolOpIdx).getExpr();
2298   emitAuipcInstPair(DestReg, TmpReg, Symbol, RISCVMCExpr::VK_RISCV_PCREL_HI,
2299                     Opcode, IDLoc, Out);
2300 }
2301 
2302 bool RISCVAsmParser::checkPseudoAddTPRel(MCInst &Inst,
2303                                          OperandVector &Operands) {
2304   assert(Inst.getOpcode() == RISCV::PseudoAddTPRel && "Invalid instruction");
2305   assert(Inst.getOperand(2).isReg() && "Unexpected second operand kind");
2306   if (Inst.getOperand(2).getReg() != RISCV::X4) {
2307     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[3]).getStartLoc();
2308     return Error(ErrorLoc, "the second input operand must be tp/x4 when using "
2309                            "%tprel_add modifier");
2310   }
2311 
2312   return false;
2313 }
2314 
2315 std::unique_ptr<RISCVOperand> RISCVAsmParser::defaultMaskRegOp() const {
2316   return RISCVOperand::createReg(RISCV::NoRegister, llvm::SMLoc(),
2317                                  llvm::SMLoc(), isRV64());
2318 }
2319 
2320 bool RISCVAsmParser::validateInstruction(MCInst &Inst,
2321                                          OperandVector &Operands) {
2322   const MCInstrDesc &MCID = MII.get(Inst.getOpcode());
2323   unsigned TargetFlags =
2324       (MCID.TSFlags >> RISCVII::ConstraintOffset) & RISCVII::ConstraintMask;
2325   if (TargetFlags == RISCVII::NoConstraint)
2326     return false;
2327 
2328   unsigned DestReg = Inst.getOperand(0).getReg();
2329   unsigned CheckReg;
2330   // Operands[1] will be the first operand, DestReg.
2331   SMLoc Loc = Operands[1]->getStartLoc();
2332   if (TargetFlags & RISCVII::VS2Constraint) {
2333     CheckReg = Inst.getOperand(1).getReg();
2334     if (DestReg == CheckReg)
2335       return Error(Loc, "The destination vector register group cannot overlap"
2336                         " the source vector register group.");
2337   }
2338   if ((TargetFlags & RISCVII::VS1Constraint) && (Inst.getOperand(2).isReg())) {
2339     CheckReg = Inst.getOperand(2).getReg();
2340     if (DestReg == CheckReg)
2341       return Error(Loc, "The destination vector register group cannot overlap"
2342                         " the source vector register group.");
2343   }
2344   if ((TargetFlags & RISCVII::VMConstraint) && (DestReg == RISCV::V0)) {
2345     // vadc, vsbc are special cases. These instructions have no mask register.
2346     // The destination register could not be V0.
2347     unsigned Opcode = Inst.getOpcode();
2348     if (Opcode == RISCV::VADC_VVM || Opcode == RISCV::VADC_VXM ||
2349         Opcode == RISCV::VADC_VIM || Opcode == RISCV::VSBC_VVM ||
2350         Opcode == RISCV::VSBC_VXM)
2351       return Error(Loc, "The destination vector register group cannot be V0.");
2352 
2353     // Regardless masked or unmasked version, the number of operands is the
2354     // same. For example, "viota.m v0, v2" is "viota.m v0, v2, NoRegister"
2355     // actually. We need to check the last operand to ensure whether it is
2356     // masked or not.
2357     if ((TargetFlags & RISCVII::OneInput) && (Inst.getNumOperands() == 3))
2358       CheckReg = Inst.getOperand(2).getReg();
2359     else if (Inst.getNumOperands() == 4)
2360       CheckReg = Inst.getOperand(3).getReg();
2361     if (DestReg == CheckReg)
2362       return Error(Loc, "The destination vector register group cannot overlap"
2363                         " the mask register.");
2364   }
2365   return false;
2366 }
2367 
2368 bool RISCVAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
2369                                         OperandVector &Operands,
2370                                         MCStreamer &Out) {
2371   Inst.setLoc(IDLoc);
2372 
2373   switch (Inst.getOpcode()) {
2374   default:
2375     break;
2376   case RISCV::PseudoLI: {
2377     MCRegister Reg = Inst.getOperand(0).getReg();
2378     const MCOperand &Op1 = Inst.getOperand(1);
2379     if (Op1.isExpr()) {
2380       // We must have li reg, %lo(sym) or li reg, %pcrel_lo(sym) or similar.
2381       // Just convert to an addi. This allows compatibility with gas.
2382       emitToStreamer(Out, MCInstBuilder(RISCV::ADDI)
2383                               .addReg(Reg)
2384                               .addReg(RISCV::X0)
2385                               .addExpr(Op1.getExpr()));
2386       return false;
2387     }
2388     int64_t Imm = Inst.getOperand(1).getImm();
2389     // On RV32 the immediate here can either be a signed or an unsigned
2390     // 32-bit number. Sign extension has to be performed to ensure that Imm
2391     // represents the expected signed 64-bit number.
2392     if (!isRV64())
2393       Imm = SignExtend64<32>(Imm);
2394     emitLoadImm(Reg, Imm, Out);
2395     return false;
2396   }
2397   case RISCV::PseudoLLA:
2398     emitLoadLocalAddress(Inst, IDLoc, Out);
2399     return false;
2400   case RISCV::PseudoLA:
2401     emitLoadAddress(Inst, IDLoc, Out);
2402     return false;
2403   case RISCV::PseudoLA_TLS_IE:
2404     emitLoadTLSIEAddress(Inst, IDLoc, Out);
2405     return false;
2406   case RISCV::PseudoLA_TLS_GD:
2407     emitLoadTLSGDAddress(Inst, IDLoc, Out);
2408     return false;
2409   case RISCV::PseudoLB:
2410     emitLoadStoreSymbol(Inst, RISCV::LB, IDLoc, Out, /*HasTmpReg=*/false);
2411     return false;
2412   case RISCV::PseudoLBU:
2413     emitLoadStoreSymbol(Inst, RISCV::LBU, IDLoc, Out, /*HasTmpReg=*/false);
2414     return false;
2415   case RISCV::PseudoLH:
2416     emitLoadStoreSymbol(Inst, RISCV::LH, IDLoc, Out, /*HasTmpReg=*/false);
2417     return false;
2418   case RISCV::PseudoLHU:
2419     emitLoadStoreSymbol(Inst, RISCV::LHU, IDLoc, Out, /*HasTmpReg=*/false);
2420     return false;
2421   case RISCV::PseudoLW:
2422     emitLoadStoreSymbol(Inst, RISCV::LW, IDLoc, Out, /*HasTmpReg=*/false);
2423     return false;
2424   case RISCV::PseudoLWU:
2425     emitLoadStoreSymbol(Inst, RISCV::LWU, IDLoc, Out, /*HasTmpReg=*/false);
2426     return false;
2427   case RISCV::PseudoLD:
2428     emitLoadStoreSymbol(Inst, RISCV::LD, IDLoc, Out, /*HasTmpReg=*/false);
2429     return false;
2430   case RISCV::PseudoFLH:
2431     emitLoadStoreSymbol(Inst, RISCV::FLH, IDLoc, Out, /*HasTmpReg=*/true);
2432     return false;
2433   case RISCV::PseudoFLW:
2434     emitLoadStoreSymbol(Inst, RISCV::FLW, IDLoc, Out, /*HasTmpReg=*/true);
2435     return false;
2436   case RISCV::PseudoFLD:
2437     emitLoadStoreSymbol(Inst, RISCV::FLD, IDLoc, Out, /*HasTmpReg=*/true);
2438     return false;
2439   case RISCV::PseudoSB:
2440     emitLoadStoreSymbol(Inst, RISCV::SB, IDLoc, Out, /*HasTmpReg=*/true);
2441     return false;
2442   case RISCV::PseudoSH:
2443     emitLoadStoreSymbol(Inst, RISCV::SH, IDLoc, Out, /*HasTmpReg=*/true);
2444     return false;
2445   case RISCV::PseudoSW:
2446     emitLoadStoreSymbol(Inst, RISCV::SW, IDLoc, Out, /*HasTmpReg=*/true);
2447     return false;
2448   case RISCV::PseudoSD:
2449     emitLoadStoreSymbol(Inst, RISCV::SD, IDLoc, Out, /*HasTmpReg=*/true);
2450     return false;
2451   case RISCV::PseudoFSH:
2452     emitLoadStoreSymbol(Inst, RISCV::FSH, IDLoc, Out, /*HasTmpReg=*/true);
2453     return false;
2454   case RISCV::PseudoFSW:
2455     emitLoadStoreSymbol(Inst, RISCV::FSW, IDLoc, Out, /*HasTmpReg=*/true);
2456     return false;
2457   case RISCV::PseudoFSD:
2458     emitLoadStoreSymbol(Inst, RISCV::FSD, IDLoc, Out, /*HasTmpReg=*/true);
2459     return false;
2460   case RISCV::PseudoAddTPRel:
2461     if (checkPseudoAddTPRel(Inst, Operands))
2462       return true;
2463     break;
2464   }
2465 
2466   emitToStreamer(Out, Inst);
2467   return false;
2468 }
2469 
2470 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVAsmParser() {
2471   RegisterMCAsmParser<RISCVAsmParser> X(getTheRISCV32Target());
2472   RegisterMCAsmParser<RISCVAsmParser> Y(getTheRISCV64Target());
2473 }
2474